From: Rob Herring <robh@kernel.org>
To: Fenglin Wu <fenglin.wu@oss.qualcomm.com>
Cc: linux-arm-msm@vger.kernel.org,
Dmitry Torokhov <dmitry.torokhov@gmail.com>,
Krzysztof Kozlowski <krzk+dt@kernel.org>,
Conor Dooley <conor+dt@kernel.org>, Lee Jones <lee@kernel.org>,
Stephen Boyd <sboyd@kernel.org>,
Bjorn Andersson <andersson@kernel.org>,
Konrad Dybcio <konradybcio@kernel.org>,
David Collins <david.collins@oss.qualcomm.com>,
Subbaraman Narayanamurthy
<subbaraman.narayanamurthy@oss.qualcomm.com>,
Kamal Wadhwa <kamal.wadhwa@oss.qualcomm.com>,
linux-input@vger.kernel.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org,
Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Subject: Re: [PATCH v6 1/2] dt-bindings: input: Add Qualcomm SPMI PMIC haptics
Date: Fri, 7 Aug 2026 10:56:40 -0500 [thread overview]
Message-ID: <20260807155640.GA893689-robh@kernel.org> (raw)
In-Reply-To: <20260806-qcom-spmi-haptics-v6-1-19fcecd5204f@oss.qualcomm.com>
On Thu, Aug 06, 2026 at 11:21:40PM -0700, Fenglin Wu wrote:
> Add binding document for the haptics module inside Qualcomm PMIC
> PMIH0108.
>
> Assisted-by: Claude:claude-4-8-opus
> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
> Signed-off-by: Fenglin Wu <fenglin.wu@oss.qualcomm.com>
> ---
> .../bindings/input/qcom,spmi-haptics.yaml | 136 +++++++++++++++++++++
> 1 file changed, 136 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/input/qcom,spmi-haptics.yaml b/Documentation/devicetree/bindings/input/qcom,spmi-haptics.yaml
> new file mode 100644
> index 000000000000..b1a69e9886ee
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/input/qcom,spmi-haptics.yaml
> @@ -0,0 +1,136 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/input/qcom,spmi-haptics.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Haptics device inside Qualcomm Technologies, Inc. PMIC
> +
> +maintainers:
> + - Fenglin Wu <fenglin.wu@oss.qualcomm.com>
> +
> +description: |
> + Certain Qualcomm PMICs integrate a haptics module, such as the HAP530_HV haptics
> + module in the PMIH0108 PMIC, which drives an LRA (Linear Resonant Actuator) with
> + an output voltage up to 10 V. Several play modes are supported in HAP530_HV:
> +
> + DIRECT_PLAY: The hardware outputs sinusoidal waveforms whose period is
> + defined by qcom,lra-period-us and whose peak voltage is defined by
> + qcom,vmax-microvolt. The driving amplitude can be scaled in the range
> + [0, 255] via a single register byte. Hardware-based LRA auto-resonance
> + tracking is enabled by default in this mode, allowing the haptics engine
> + to follow the actual resonant frequency of the LRA and update the driving
> + period accordingly to achieve stronger vibration magnitude.
> +
> + FIFO: The hardware can play an arbitrary waveform composed of a sequence
> + of 8-bit samples at a configurable play rate. Samples are pre-filled
> + into the internal FIFO memory of the haptics module and continuously
> + replenished via the FIFO-empty IRQ until all samples have been played.
> + An 8K-byte FIFO memory bank is available in the HAP530_HV haptics module,
> + shared between the FIFO and PAT_MEM play modes. The memory partition
> + between the two modes is configurable via registers, and FIFO mode always
> + uses the 1st partition starting from offset 0.
> +
> + PAT_MEM: This mode is very similar to FIFO streaming mode but without the
> + data refilling capability. It is designed mainly for short, latency-critical
> + vibrations. The memory space for PAT_MEM mode must be reserved for dedicated
> + usage, and the waveform data should be preloaded and remain unchanged
> + thereafter. The haptics module can play the waveform data from the memory
> + region specified by the PAT_MEM play start address and length registers.
> +
> + In either FIFO mode or PAT_MEM mode, the following play rates are supported:
> + -- 0(T_LRA): each FIFO byte drives one full sinusoidal cycle with the
> + period defined in qcom,lra-period-us.
> + -- 1/2/3(T_LRA_DIV_2/4/8): each FIFO byte drives a half/quarter/eighth
> + sinusoidal cycle with the period defined in qcom,lra-period-us.
> + -- 4/5/6(T_LRA_X_2/4/8): each FIFO byte drives 2/4/8 sinusoidal cycles
> + with the period defined in qcom,lra-period-us.
> + -- 8/9/10/11/12/13(8KHz/16KHz/24KHz/32KHz/44.1KHz/48KHz): the FIFO
> + data is treated as PCM samples and drives the output with an
> + arbitrarily shaped waveform. This mode is typically used to define
> + custom driving waveforms for specific vibration effects such as fast
> + attack, crisp brake, etc.
> +
> + The drive voltage in FIFO or PAT_MEM mode can exceed the value defined in
> + qcom,vmax-microvolt to achieve a special vibration effect, but the waveform
> + must be short enough to prevent the LRA from being damaged by operating at
> + an overvoltage.
> +
> + Also, hardware-based LRA auto-resonance tracking is normally disabled in
> + FIFO or PAT_MEM mode, as these modes are intended to drive arbitrary
> + waveforms that may not follow the resonant frequency; autonomous hardware
> + resonance correction would interfere with the intended output.
> +
> +properties:
> + compatible:
> + items:
> + - const: qcom,pmih0108-haptics
> + - const: qcom,spmi-haptics
> +
> + reg:
> + items:
> + - description: HAP_CFG module base address
> + - description: HAP_PTN module base address
> +
> + reg-names:
> + items:
> + - const: cfg
> + - const: ptn
> +
> + interrupts:
> + maxItems: 1
> +
> + interrupt-names:
> + items:
> + - const: fifo-empty
> +
> + qcom,vmax-microvolt:
> + description:
> + Maximum allowed output driving voltage in microvolts, must be a multiple
> + of 50,000 uV. This is the peak driving voltage in DIRECT_PLAY mode,
> + which outputs sinusoidal waveforms. The value should be equal to the
> + square root of 2 times the Vrms voltage of the LRA.
> + minimum: 50000
> + maximum: 10000000
> + multipleOf: 50000
> +
> + qcom,lra-period-us:
> + description:
> + LRA actuator initial resonance period in microseconds
> + (1,000,000 / resonant_freq_hz). Used to configure T_LRA-based play
> + rates and the auto-resonance zero-crossing window. It could be also used
> + as the initial period if the LRA wants to be driven off resonance.
> + minimum: 5
> + maximum: 20475
> + multipleOf: 5
> +
> +required:
> + - compatible
> + - reg
> + - reg-names
> + - interrupts
> + - interrupt-names
> + - qcom,vmax-microvolt
> + - qcom,lra-period-us
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + #include <dt-bindings/interrupt-controller/irq.h>
> +
> + pmic {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + haptics@f000 {
No incomplete examples please. Put this in the example for the PMIC.
And please comment on sashiko report. Looks valid to me.
Rob
next prev parent reply other threads:[~2026-08-07 15:56 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-07 6:21 [PATCH v6 0/2] input: misc: Add an initial driver for haptics inside Qcom PMIH010x PMIC Fenglin Wu
2026-08-07 6:21 ` [PATCH v6 1/2] dt-bindings: input: Add Qualcomm SPMI PMIC haptics Fenglin Wu
2026-08-07 6:29 ` sashiko-bot
2026-08-07 15:56 ` Rob Herring [this message]
2026-08-07 6:21 ` [PATCH v6 2/2] input: misc: Add Qualcomm SPMI PMIC haptics driver Fenglin Wu
2026-08-07 6:39 ` sashiko-bot
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